Differential Diagnosis
- Single most likely diagnosis
- Chronic Lymphocytic Leukemia (CLL): The presence of CD45+, CD5+, CD19+, CD20+ (dim), CD22+ (dim), and CD23+ is highly suggestive of CLL. The dim expression of CD20 and CD22, along with the presence of CD23, are characteristic of this disease.
- Other Likely diagnoses
- Mantle Cell Lymphoma (MCL): Although less likely than CLL, MCL can also express CD5 and CD19. However, MCL typically has brighter CD20 expression and often lacks CD23.
- Follicular Lymphoma: This diagnosis is less likely due to the absence of CD10, but some cases of follicular lymphoma can be CD10 negative. The presence of CD5 and CD23 would be unusual for follicular lymphoma.
- Do Not Miss
- Richter's Transformation: This is a transformation of CLL to a more aggressive lymphoma, often diffuse large B-cell lymphoma. Although the immunophenotype provided does not strongly suggest this diagnosis, it is crucial not to miss it due to its aggressive nature and different treatment approach.
- Prolymphocytic Leukemia: This rare leukemia can present with a similar immunophenotype to CLL but typically has brighter expression of surface immunoglobulin and often lacks CD23.
- Rare diagnoses
- B-cell Prolymphocytic Leukemia (B-PLL): Characterized by a high proportion of prolymphocytes in the blood, B-PLL can have a similar immunophenotype to CLL but usually lacks CD23 and has brighter sIg expression.
- Splenic Marginal Zone Lymphoma (SMZL): This rare lymphoma can have a variable immunophenotype, but the presence of CD5 and CD23 would be unusual. SMZL often lacks CD5 and can have a distinct pattern of villous lymphocytes in the blood.